Introduction. The paper presents the results of the studies on assessing the quality of the aquatic ecosystem of a lake located within the city. The European perch (Perca fluviatilis L.) and the Gibel carp (Carassius gibelio) were used as an indicator for determining the quality of the aquatic ecosystem by the method of fluctuating asymmetry.
Problem Statement. The aim of the work was to conduct monitoring with the subsequent assessment of the quality of the ecosystem of the city lake using the method of fluctuating asymmetry (hereinafter FA).
Theoretical and Practical Part. The quality of the urban lake aquatic ecosystem was assessed using the FA method (indicators: the European perch (Perca fluviatilis L.), 1758 and the Gibel carp (Carassius auratus Bloch), 1783). To identify the reasons for the high PFA values, a chemical analysis (in an accredited laboratory) of the gills of the Gibel carp for heavy metals was performed.
Conclusions. As a result of the research, the FA indicators values for these indicators were obtained. According to the results of a laboratory study of the content of heavy metals in the gill arches of the Gibel carp, an excess of the maximum permissible concentration of 8 out of 10 analyzed elements was revealed. It has been established that the ecosystem of the city lake Kenon is experiencing a significant anthropogenic load (5 points — the critical quality of the aquatic environment) and it continues to increase towards the deterioration of the habitat.
Adult female European perch (Perca fluviatilis) from the Baltic Sea show no evidence of thiamine deficiency
